* {
    margin: 0px;
    padding: 0px;
}

html,
body {
    height: 100%;
    width: 100%;
}
.main{
    width: 300px;
    height: 400px;
    margin: 0px auto;
}
.main .display {
    height: 200px;
    width: 400px;
    background-color: rgb(233, 233, 233);
    /* border: solid rgb(255,255,255) 1px; */
}

.main .display .line {
    height: 100px;
    line-height: 120px;
    text-align: right;
    font-size: 30px;
    padding-right: 10px;
    box-sizing: border-box;
}

.main .display .line#first-line {
    letter-spacing: 12px;
}

.main .display .line#second-line {
    font-size: 50px;
    line-height: 120px;
}

.main .btn .table {
    width: 400px;
    height: 500px;
    text-align: center;
    font-size: 30px;
    border: solid rgb(215, 215, 215) 1px;
}

.table td {
    width: 100px;
}

.main .btn .table .num {
    background-color: rgb(224, 224, 224);
}

.main .btn .table .step {
    background-color: rgb(245, 146, 51);
    color: white;
}

.main .btn .table .other {
    background-color: rgb(214, 214, 214);
}

.main .btn .table .other:active {
    background-color: rgb(200, 200, 200);
}

.main .btn .table .num:active {
    background-color: rgb(200, 200, 200);
}